This invention is directed to an electronic watch construction which includes an electrically conductive resilient pad between the battery and the electronic substrate to assure positive electric contact and to spread mechanical shock loading on the substrate.
An electronic watch is a precision electronic device. Electronic devices require an insulator substrate upon which circuits can be printed and structures can be attached. The mounting of an integrated circuit chip on a substrate and its electrical connection to printed circuitry on the substrate require structures of great dimensional stability. Ceramic substrates have the desirable characteristics of receiving printed circuitry, dimensional stability, suitable attachment structure for integrated circuit chips and other mechanical attachments, and are inexpensive and reliable in use.
The electric contacts to which the batteries are connected are usually formed directly on one side of the substrate to minimize the number of interconnections. When the battery rests directly against the substrate and the watch is dropped, the shock force of the battery acting against the substrate causes the substrate to crack, unless special shock mounting for the substrate is provided.
In the past, the substrate has been mounted for both lateral and axial (of the watch, perpendicular to the face) shock motion by resilient shock mounting. This protects the substrate and the rest of the shock mounted structure, but, of course, requires special design to accomplish the shock mounting. Thus, in the past, without special shock mounting, ceramic and other brittle material substrates could be broken within the watch by mechanical shock. The watch construction of this invention increases the amount of permissible mechanical shock applied to the watch without substrate breakage, as compared to a rigidly mounted substrate without this construction.